when i brought my car the guy said that the engine had ben taken out of a1999 or 2000 Z71 but he wasnt sure i have asked around but to no avail no one seems to know where the serial number is located. if any one can help me please help i realy need to know what size engine is in my car so i can tune it and get tho proper performance up grades also if any one have any upgrade ideas they will be greatly appreciated thanks  

Hi, for small block chevy, Starting in 1970, the serial number is stamped either above the oil filter, somewhere on the block pad (in front of the cylinder head), or on the transmission flange somewhere.
VIN code format Example: 13N100001
(1 = Chevrolet, 3 = 1973, N = Norwood, 100001 = Production sequence of vehicle VIN)
I have found this site helpful for older castging numbers ETC. http://www.nastyz28.com/sbchevy/sblock.html#vincode I hope that helps  

thaks